|
|||
|
|||
Northern Gannet colony of Sep-Ihes followed with GPS-loggers The Réserve Naturelle Nationale (RNN) des Sept-Iles
hosts the unique French colony of Northern Gannets. The tracking of the colony
is carried out by the CNRS (Centre National de Recherche
Scientifique) team in Montpellier
(Centre of Functional and evolutionary Ecology), in partnership with the LPO staff (Ligue pour la Protection
des Oiseaux) based on the reserve. In 2010, the tracking of the colony enabled the estimation of the breeding population (between 21 847 and 21 921 pairs) and the chronology of reproduction. Thus, over a quarter (28%) of egg laying occurred on April 19 (+ / - 3 days), and by this date, 62.2% of individuals had already laid. Photo: Attaching a GPS-log to a Northern Gannet - Rouzic (RNN des Sept-Iles, 22) |
|||
In parallel, in 2010, GPS logs were deployed on 35 breeding individuals to track their feeding trips during the nesting period. The data could be recovered on 25 of them, totalyzing 64 trips. It showed that birds fed in the western English Channel, between the French and English coasts, at an average distance of 128 kilometres (max = 252 km / min = 206 km) from the colony, giving an average total trip of 507 kilometres. However these trips are different according to individuals. The duration, in effect, varied between 7 minutes and 35 hours. The longest trip was 1076 kilometres, realized in 21 hours. |
|||
The data obtained from GPS-logs deployed within
the framework of the program FAME will allow an improvement in the understanding
of the trips of Gannets out of the breeding season, and also the loyalty of
individuals to the wintering sites. Various additional
samples were taken during the installation of the logging equipment. These samples, which will improve knowledge of
the diet of this species, are being analyzed. These results show a strong repeatability of
the offshore trips made by birds, so the data from a single trip should be sufficient to know the feeding destination of individuals.Map representing the offshore trips (4) of breeding individuals from 03 to 07 June 2010 - Rouzic (RNN des Sept-Iles, 22) |